Cargo carrying containers, such as truck trailers or containers, commonly use rectangular pivoted double doors on a rear end wall for loading and unloading cargo from the container. Because the doors generally comprise the entire rear end wall of the container, there is little bracing or other container support, and the frame is thus easily subjected to rack distortion. Once the frame is distorted, proper engagement between the doors and frame is often difficult to achieve and maintain. Various door control mechanisms have been used in the past to urge the doors to the closed position, and to resist and reduce racking once the doors are closed.
Such mechanisms are disclosed, for example, in U.S. Pat. Nos. 3,695,661 and 4,601,501. They include lock rods or shafts mounted on and extending the height of the door. The shafts include cam members secured to opposite shaft ends for engagement with keeper members mounted on the associated door frame. Often two lock rods or additional latch members extending laterally from the shafts have also been provided, as in U.S. Pat. No. 3,737,183, at locations intermediate the cam and keeper members. These intermediate latch members are provided to further assist in aligning and closing the doors, and are positioned to bridge the central juncture between two pivoted doors. The latch member extends from a shaft secured to one door, while the associated keeper is secured to an adjacent door for engagement by the latch member.